This invention relates to a hot forging machine having a die preheating unit fitted outsides of the machine body thereof.
The conventional forging machines for forging heated blanks or work pieces are disadvantageous in that, when there is a remarkable temperature difference between the work peices to be forged and dies, the dies attahced to slides and bolsters are preheated directly by means of gas burners in the forging machine for the purpose of preventing deformation and damage of the dies due to thermal expansion thereof, and the preheating time is about half an hour, although it depends on the size of dies, and during the preheating the hot forging operation is required to be interrupted thereby reducing the operation efficiency so much.